The patent literature relating to portable, hand held, power saw guides, both for shorter cut-off or crosscut operations, or for longer cuts in a workpiece, is full of listing the difficulties of freehand guiding of a power saw to effect an accurate cut. Thus the need for a saw guide. Most types of guides make use of the fact that for each saw, there is a constant distance from the saw blade and its associated kerf to either edge of the saw table (or foot, or shoe, or plate) that is parallel to the saw blade. In addition to the basic saw guide designs, there have been many designs to provide a gauging means so as to accurately position the saw guide relative to the line of cut desired. However, some or all of these gauging designs have had one or more of the following limitations:
(a) Both hands were needed--one to hold, position, and then clamp the guide; and the other hand to move the gauge from the storage position to the measure position and then back to the storage position before the saw could be picked up and the cutting operation could begin. PA0 (b) A pencil line had to be drawn across the full top surface where the cut was desired. This operation is an extra step for most cuts and takes time. PA0 (c) The gauge had to be calibrated to the saw and to the blade thickness using a mechanically adjustable pointer(s). This mechanical adjustment takes time and has to be re-calibrated every time a different bevel angle setting of the saw blade is used other than the standard square setting. Also there can be some degree of error in this mechanical setting since it is an artificial and once removed representation from the actual cut. Also, the calibration is lost every time there is a re-calibration. PA0 (d) The gauge setting was good for just one saw with one particular blade; if another saw with its blade on a job site were to be used, the gauge would have to again be re-calibrated, and again the first calibration would be lost, requiring another re-calibration from scratch. PA0 (e) Positioning the gauge on the workpiece, then measuring and marking the workpiece against the gauge, and then re-positioning of the guide. PA0 (f) Only one side of the saw kerf would be shown by the gauge since the kerf area and the other side of the kerf would be cut off from the gauge during calibration or actual use. Thus cutting on only one side of the line could be determined with the gauge. PA0 (g) The gauge could not be brought right up against the cutting mark or line, but only brought up close to the line, permitting a parallax error to occur during positioning. PA0 (h) The guide clamping means was too slow a process.
The net effect of these complications was that, though the gauge would position the guide, it was too cumbersome and slow a process to be employed at the jobsite. And without an accurate and quick gauging means, it became too cumbersome and slow to position a guide by means of trial and error. As a result, most carpenters, on most jobsites, just cut lumber freehand without any guide.
A very large percentage of cuts with a hand power saw in construction work involve the cut-off type of cut, that is, cutting a 1.times.4, 2.times.4, 2.times.6, etc first square at one end if necessary and then cutting it to proper length, again with a square cut.
An object of this invention is to provide a cut-off guide with gauge that is fully operable with only one hand during the entire procedure.
A further object of this invention is to provide a versatile, quick, accurate, permanent, and interchangeable gauging apparatus which shows both sides of the saw kerf.
Yet another object of this invention is to eliminate the step, for square cuts, of drawing a square line across the workpiece after the workpiece is measured and marked to length.
Still another object is to provide both the fixed square guide and the angle adjustable guide. Both embodiments are shown.
The above objects, achieved in this invention, make the saw guide with gauge a quicker, easier, and more accurate method of cutting-off lumber than by the freehand method. Thus a more accurate and stronger product should result in less time with less effort than with the freehand method or with earlier types of saw guides employed.